1. Field of Invention
This invention is directed to ink jet printers.
2. Description of Related Art
In operating ink jet printers and other devices that use ink jet technology, print heads that contain ink fire ink onto paper or other printable media through jets located in the print heads. Firing the individual jets of the ink jet print head is determined by the firing pulse of the system that operates the ink jet print head.
Data is transferred to the print heads by a control circuit. The control circuit controls the logic that determines how many jets to fire at a time and when to fire the jets. The data is held in the print heads until a fire pulse activates the print heads and the jets are fired. Typically four or eight jets are fired at a time. Each set of jets are fired sequentially until all the jets in the print head have been fired for the current position of the print head.
In operating an ink jet printer, smart logic ink jet print heads typically use a serial shift system to clock data into the print head. This information is decoded and used to determine which jets to fire. The first set of data is shifted into a register and then fired by an enable pulse. At the same time this first set is being fired, a second set of data is loaded into the register for the next set of jets to be fired. Once the first set of jets are fired, the second set can be fired using the second set of data loaded into the register, while a third set of data is loaded. This is continued until all the jets in the head have been fired for the current position of the print head.
However, in most ink jet printing devices, two extra pulses are needed to operate the jets. The first pulse is used to load the first set of data into the register. The second pulse is used to fire the last set of data.
This invention provides ink jet printing systems and methods that improve the efficiency and increase the speed of ink jet printing.
This invention separately provides double banking and/or ping-ponging ink jet printing systems and methods that eliminate the two extra pulses needed to operate the jets.
In various exemplary embodiments of the systems and methods according to this invention, double banking is used by adding a buffer between the shift register and the firing logic. The buffer or storage register eliminates the need for the two extra pulses.
In other exemplary embodiments of the systems and methods according to this invention, alternating, or xe2x80x9cping-pongingxe2x80x9d, between two buffers or registers is used to eliminate the need for the two extra pulses. Two different buffers or registers are used to store the data from the shift register. The two registers are alternatively selected. When one buffer or register is being fired using a current set of data, the other is loaded with the next set of data.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of the apparatus/systems and methods according to this invention.